JP2005296907A - Coating film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating film forming apparatus for forming a coating film having excellent film thickness uniformity.
A resist coating apparatus (CT) 11 includes a mounting table 51 on which a substrate G is mounted, a resist nozzle 52, first and second nozzle lifting mechanisms 54a and 54b, and first and second nozzle lifting mechanisms. First and second lifting control devices 55a and 55b for controlling driving of 54a and 54b, a nozzle slide mechanism 56 for integrally sliding the registration nozzle 52 and the first and second nozzle lifting mechanisms 54a and 54b, and a substrate The first and second displacement sensors 58a and 58b for detecting the undulation of G, a delay operation for a predetermined time on the measured values by the displacement sensors 58a and 58b, and the first and second lift control devices 55a and 55b for sending the delay signals. The second buffer devices 86a and 86b and the delay time generation device 87 for determining the delay time in the first and second buffer devices 86a and 86b. The raising and lowering of the resist nozzle 52 and the posture control are performed in response to the undulation of the substrate G.
[Selection] Figure 1

Description

  The present invention relates to a coating film forming apparatus, and more specifically, forms a coating film by supplying a predetermined coating liquid to a substrate such as a glass substrate used in an FPD (flat panel display) such as a liquid crystal display (LCD). The present invention relates to a coating film forming apparatus.

  For example, in a manufacturing process of a liquid crystal display device (LCD), a predetermined circuit pattern is formed on a glass substrate by using a photolithography technique. That is, a resist solution is supplied to a glass substrate to form a coating film, which is dried and heat-treated, and then subjected to exposure processing and development processing sequentially.

  Here, as an apparatus for supplying a resist solution to a glass substrate to form a coating film, a mounting table that horizontally vacuum-sucks the glass substrate and a resist supply that supplies the resist solution to the glass substrate held on the mounting table There is known a coating film forming apparatus having a nozzle, and a moving mechanism that relatively moves the mounting table and the resist supply nozzle in the horizontal direction (see, for example, Patent Document 1 and Patent Document 2). In such a coating film forming apparatus, the height of the resist supply nozzle when supplying the resist solution to the glass substrate is kept constant.

However, recently, the length of one side of the glass substrate has exceeded 2 m. In such a glass substrate, undulation may occur when it is placed on the mounting table. If the height is kept constant, the distance between the resist solution discharge port of the resist supply nozzle and the surface of the glass substrate will change sequentially due to the waviness of the glass substrate, which reduces the film thickness uniformity of the coating film. Will occur.
Japanese Patent Laid-Open No. 10-156255 JP 2001-310152 A

  This invention is made | formed in view of such a situation, and it aims at providing the coating film formation apparatus which can form the coating film excellent in film thickness uniformity.

According to a first aspect of the present invention, there is provided a coating film forming apparatus that forms a coating film by supplying a predetermined coating liquid to a substrate held in a substantially horizontal posture.
A coating liquid nozzle having a coating liquid discharge port for discharging a predetermined coating liquid;
A nozzle lifting mechanism for lifting and lowering the coating liquid nozzle;
A lifting control device for performing lifting control of the nozzle lifting mechanism;
A moving mechanism for relatively moving the substrate and the coating liquid nozzle;
A displacement sensor for measuring the waviness of the substrate in a predetermined distance forward from the coating liquid discharge port in the direction in which the coating liquid is applied by the coating liquid nozzle;
A buffer device for performing a delay operation for a predetermined time on the measurement value by the displacement sensor and sending the delay signal to the elevation control device;
A delay time generating device for determining a delay time in the buffer device;
Comprising
When forming the coating film on the surface of the substrate by relatively moving the substrate and the coating solution nozzle while discharging the coating solution from the coating solution nozzle, the elevating control device is configured to use the coating solution nozzle. There is provided a coating film forming apparatus characterized in that the coating liquid nozzle is moved up and down in accordance with the undulation of the substrate so that the distance between the coating liquid discharge port and the substrate is constant.

According to a second aspect of the present invention, there is provided a coating film forming apparatus for forming a coating film by supplying a predetermined coating liquid to a substrate held in a substantially horizontal posture.
An elongated coating liquid nozzle having a coating liquid discharge port for discharging a predetermined coating liquid in a substantially strip shape;
A first nozzle lifting mechanism that substantially holds one end of the coating liquid nozzle in the longitudinal direction and lifts the coating liquid nozzle;
A second nozzle raising / lowering mechanism that substantially holds the other end in the longitudinal direction of the coating liquid nozzle and raises and lowers the coating liquid nozzle;
A first elevating control device for performing elevating control of the first nozzle elevating mechanism;
A second lifting control device for performing lifting control of the second nozzle lifting mechanism;
A moving mechanism including a motor and a linear scale for relatively moving the substrate and the coating liquid nozzle;
A first displacement sensor and a second displacement sensor for measuring the waviness of the substrate at a predetermined distance in front of the coating solution discharge port in the direction in which the coating solution is applied by the coating solution nozzle and at the end of the substrate;
A first buffer device that performs a delay operation for a predetermined time on a measured value by the first displacement sensor, and sends the delay signal to the first lifting control device;
A second buffer device that performs a delay operation for a predetermined time on a measurement value obtained by the second displacement sensor, and sends the delay signal to the second lift control device;
A delay time generating device for determining a delay time in the first buffer device and the second buffer device;
Comprising
When forming a coating film on the surface of the substrate by relatively moving the substrate and the coating solution nozzle while discharging the coating solution from the coating solution nozzle, the first elevating control device and the second The elevation controller controls the elevation and inclination of the coating solution nozzle in accordance with the undulation of the substrate so that the distance between the coating solution discharge port of the coating solution nozzle and the substrate is constant. A coating film forming apparatus is provided.

  According to the present invention, since the distance between the surface of the substrate and the coating liquid discharge port of the coating liquid nozzle is kept constant corresponding to the undulation and thickness unevenness of the substrate, coating with excellent film thickness uniformity A film can be formed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, the case where the present invention is applied to an apparatus for forming a resist film on the surface of a glass substrate for LCD (hereinafter referred to as “LCD substrate”) will be described.

  FIG. 1 is a plan view showing a schematic structure of a resist processing unit 10 for forming a resist film (coating film) on the LCD substrate G. FIG. 2 is a front view showing a schematic structure of the resist coating apparatus (CT) 11 (viewed from the X direction in FIG. 1 and a part thereof is shown in cross section). Further, FIG. 3 shows a schematic control block diagram of the resist coating apparatus (CT) 11.

  The resist processing unit 10 includes a resist coating device (CT) 11 that applies a resist solution to the LCD substrate G to form a coating film, and a reduced pressure that dries the coating film formed on the LCD substrate G by holding it in a reduced-pressure atmosphere. A drying device (VD) 12 and a substrate transfer device 13 for transferring the LCD substrate G from the resist coating device (CT) 11 to the reduced pressure drying device (VD) 12 are provided.

  The resist coating apparatus (CT) 11 includes a mounting table 51 for mounting the LCD substrate G in a substantially horizontal posture, a resist nozzle 52 for applying a resist solution to the LCD substrate G mounted on the mounting table 51, and a resist nozzle 52. A resist solution supply mechanism 53 that controls the supply of the resist solution to the resist and the discharge of the resist solution from the resist nozzle 52, first and second nozzle elevating mechanisms 54a and 54b that elevate and lower the resist nozzle 52, and a first nozzle elevating mechanism 54a The first lifting control device 55a for controlling the driving of the second nozzle, the second lifting control device 55b for controlling the driving of the second nozzle lifting mechanism 54b, the resist nozzle 52, and the first and second nozzle lifting mechanisms 54a and 54b are integrated. A nozzle slide mechanism 56 for sliding in the X direction, a nozzle cleaning unit 57 for cleaning the resist nozzle 52, and a mounting table. Comprises a displacement sensor 58a · 58b for detecting the undulation of the placed LCD substrate G to 1, a resist coating unit (CT) 11 coating processing control unit 59 controls the whole, the.

  Further, the resist coating device (CT) 11 performs a delay operation for a predetermined time on the measurement value by the displacement sensor 58a, and the first buffer device 86a that sends the delay signal to the first elevation controller 55a and the measurement by the displacement sensor 58b. A delay operation is performed on the value for a predetermined time and the delay signal is sent to the second lifting control device 55b. The delay time generator 87 determines the delay time in the first and second buffer devices 86a and 86b. It has.

  A plurality of suction holes (not shown) are provided at predetermined positions on the surface of the mounting table 51 so that the LCD substrate G can be adsorbed under reduced pressure. In addition, elevating pins 61 that are movable up and down by an elevating device (not shown) are provided at predetermined positions so as to penetrate the mounting table 51 in the vertical direction. These lift pins 61 lift and lower the LCD substrate G when the LCD substrate G is carried into the mounting table 51 from the outside and when the LCD substrate G on which the resist film is formed is unloaded from the mounting table 51.

  As shown in the schematic perspective view of FIG. 4, the resist nozzle 52 is provided with a slit-like resist discharge port 52b for discharging a resist solution in a substantially strip shape in a long box body 52a that is long in one direction. It has a structure. The resist nozzle 52 is held in a substantially horizontal posture with the longitudinal direction of the box 52a aligned with the Y direction (see FIG. 1). Although the detailed configuration of the resist solution supply mechanism 53 is not shown, a tank that stores the resist solution, a pump that sends the resist solution from the tank to the resist nozzle 52, and a valve that controls the discharge timing of the resist solution from the resist discharge port 52b. Etc.

  The resist nozzle 52 is held by the holding members 62a and 62b at the end surfaces in the Y direction, and the first and second nozzle lifting mechanisms 54a and 54b support the holding members 62a and 62b, respectively.

  As shown in FIG. 3, the first nozzle lifting mechanism 54a includes a motor unit that moves the holding member 62a and an encoder unit that measures the amount of movement of the holding member 62a by driving the motor unit. The value measured by the encoder unit and the height position of the resist nozzle 52 are linked in advance, and the height of one end of the resist nozzle 52 can be adjusted by measuring the movement amount of the holding member 62. ing. Similarly, the second nozzle raising / lowering mechanism 54b also includes a motor unit and an encoder unit that measures the amount of movement of the holding member 62b by driving the motor unit, that is, the height position of the other end of the resist nozzle 52.

  Since the first and second nozzle elevating mechanisms 54a and 54b can change the heights of the holding members 62a and 62b independently, the resist nozzle 52 is moved up and down as a whole. In addition, the resist nozzle 52 can be slightly tilted by slightly changing the height of the holding members 62a and 62b.

  However, since the position of the resist nozzle 52 needs to be precisely controlled, the resist nozzle 52 is firmly held by the holding members 62a and 62b, and the holding members 62a and 62b are also respectively the first and second nozzle elevating mechanisms 54a and 54a. Since the resist nozzle 52 needs to be held firmly, there is a structural limit in tilting the resist nozzle 52.

  For this reason, the coating treatment control device 59 prevents the first and second nozzles from deviating from a certain range due to an erroneous sensing or the like by the displacement sensors 58a and 58b. The measured values by the encoder units of the elevating mechanisms 54a and 54b are monitored, and when the difference between these measured values exceeds a predetermined value, the first and second elevating control devices 55a and 55b are respectively set. Accordingly, the driving of the first and second nozzle elevating mechanisms 54a and 54b is stopped. This prevents the occurrence of an accident such as damage to the attachment portion between the resist nozzle 52 and the holding members 62a and 62b, or deformation of the resist nozzle 52 itself.

  The first and second nozzle elevating mechanisms 54a and 54b are appropriately selected from an electromagnetic linear motor, a ball screw, a belt driving device, or the like as long as the accuracy of the elevating operation of the registration nozzle 52 can be ensured. it can.

  The nozzle slide mechanism 56 includes guides 65a and 65b extending in the X direction, slide stages 66a and 66b fitted to the guides 65a and 65b, respectively, and linear motors 67a and 67b. The first nozzle lifting mechanism 54a is attached to the slide stage 66a, and the second nozzle lifting mechanism 54b is attached to the slide stage 66b.

  The linear motor 67a includes a magnet rail 81a extending in the X direction, a coil 82a attached to the slide stage 66a and disposed in the magnet rail 81a, a linear scale 83 extending in the X direction, and the linear scale 83. A reading head 84 and a motor control device 85 that sends a predetermined drive signal to the coil 82a are provided. The linear motor 67b includes a magnet rail 81b extending in the X direction, and a coil 82b attached to the slide stage 66b and inserted into the magnet rail 81b.

  As is well known, the magnet rails 81a and 81b have a structure in which S poles and N poles are alternately provided in the X direction at a predetermined interval, and a magnetic field generated by flowing a predetermined current through the coils 82a and 82b and this magnetic field. The coils 82a and 82b and the slide stages 66a and 66b are integrally moved in the X direction by the attractive force and the repulsive force between the magnetic rails 81a and 81b.

  The motor control device 85 compares the read value of the head 84 with the instruction value sent from the coating processing control device 59 to move the registration nozzle 52 to a predetermined position, and arranges the slide stages 66a and 66b in the Y direction. In order to move in the X direction in a state, a predetermined drive signal is sent simultaneously to the coils 82a and 82b. In the resist coating process, since it is preferable to move the resist nozzle 52 with high accuracy, a high-resolution glass scale having a resolution of, for example, 0.05 μm is preferably used as the linear scale 83.

  The nozzle cleaning unit 57 is provided on the opposite side of the reduced pressure drying device (VD) 12 with the mounting table 51 interposed therebetween. The nozzle cleaning unit 57 is also a place where the resist nozzle 52 is retracted when the LCD substrate G is carried into the mounting table 51. Although the detailed structure of the nozzle cleaning unit 57 is not shown, the nozzle cleaning unit 57 performs so-called dummy dispensing in which the resist solution is preliminarily discharged from the resist nozzle 52 before the resist solution is supplied to the LCD substrate G. A dummy dispensing unit for the resist nozzle 52, a nozzle bath for holding the resist discharge port 52b in a solvent (for example, thinner) vapor atmosphere so that the resist discharge port 52b of the resist nozzle 52 is not dried, and a resist discharge port 52b of the resist nozzle 52 A nozzle cleaning mechanism for removing the resist adhering to the vicinity.

  The displacement sensors 58a and 58b are attached to the side surface of the resist nozzle 52 in the X direction (side surface on the nozzle cleaning unit 57 side) so as to always sense in the vertical direction even when the resist nozzle 52 is tilted by a slight angle. The distance between the surface of the LCD substrate G immediately below the displacement sensors 58a and 58b and the displacement sensors 58a and 58b is measured. Here, since the displacement sensors 58a and 58b are attached to the resist nozzle 52, the distance between the surface of the LCD substrate G measured by the displacement sensors 58a and 58b and the displacement sensors 58a and 58b is respectively the LCD substrate G. The first and second lifting / lowering control devices 55a and 55b are converted into a distance between the surface of the first nozzle and the resist discharge port 52b of the resist nozzle 52.

  As will be described in detail later, the measurement signal of the displacement sensor 58a is sent to the first buffer device 86a, where a delay process for a predetermined time is performed, and then sent to the first lifting control device 55a. Similarly, the measurement signal of the displacement sensor 58b is sent to the second buffer device 86b, where a delay process for a predetermined time is performed, and then sent to the second lifting control device 55b. The delay processing time is determined by the delay time generator 87.

  The reduced pressure drying apparatus (VD) 12 includes a mounting table 68 for mounting the LCD substrate G, and a chamber 69 for storing the LCD substrate G mounted on the mounting table 68. Proximity pins (not shown) for supporting the LCD substrate G are provided at predetermined positions on the surface of the mounting table 68 provided in the vacuum drying apparatus (VD) 12. The chamber has an upper and lower divided structure composed of a fixed lower container and a freely movable upper lid.

  The substrate transfer arm 13 is movable in the X direction, Y direction, and Z direction (vertical direction), and holds the LCD substrate G by suction in the vicinity of the end surface in the Y direction on the back surface of the LCD substrate G. The substrate transfer arm 13 receives the LCD substrate G from the lifting pins 61 on the mounting table 51 of the resist coating device (CT) 11 and mounts the LCD substrate G held on the mounting table 68 of the reduced pressure drying device (VD) 12. To do.

  Next, control of resist solution application in the resist coating apparatus (CT) 11 will be described. FIG. 5 shows a side view of the positional relationship between the displacement sensors 58a and 58b and the registration nozzle 52 as seen from the Y direction. FIG. 6A is a YZ sectional view showing a state where the resist discharge port 52b of the resist nozzle 52 is positioned on the point P shown in FIG. 5, and FIG. 6B is a Q view shown in FIG. YZ sectional drawing which shows the state in which the resist discharge port 52b of the resist nozzle 52 is located on the point is shown, respectively.

  FIG. 5 shows a part of the LCD substrate G, in which the LCD substrate G is not completely horizontal but is mounted on the mounting table 51 with a slight undulation. Such undulation is likely to occur on a large LCD substrate G. For example, when the LCD substrate G is placed on the mounting table 51 and vacuum-sucked, the LCD substrate G is in close contact with the mounting table 51 in the portion where the suction hole is formed, but the other portion is lifted, Such swell may occur.

  5 and 6, the LCD substrate G is in close contact with the mounting table 51 in the Y direction passing through the point P. However, in the Y direction passing through the Q point, the LCD substrate G is separated from the mounting table 51 on the first nozzle lifting mechanism 54a side. It floats slightly, and is further lifted from the mounting table 51 on the second nozzle lifting mechanism 54b side than on the first nozzle lifting mechanism 54a side. 5 and 6 show the waviness of the LCD substrate G extremely large, for example, the height difference is at most 100 μm or less.

  Since the LCD substrate G is horizontal in the portion shown in FIG. 6A, the resist nozzle 52 is also held horizontally. Thereby, the distance between the resist discharge port 52b of the resist nozzle 52 and the LCD substrate G is maintained constant at the distance η as a whole. If the resist nozzle 52 is scanned toward the Q point side while maintaining the orientation of the resist nozzle 52 horizontally, the LCD substrate G is lifted, and therefore the distance between the resist discharge port 52b and the LCD substrate G Becomes shorter than the distance η. Due to such a change in the distance between the surface of the LCD substrate G and the resist discharge port 52b, uneven coating such as non-uniform thickness may occur when the resist solution is applied to the LCD substrate G. .

  In order to prevent this, as shown in FIG. 6B, the rising distances of the first and second nozzle lifting mechanisms 54a and 54b are independently adjusted to correspond to the undulation of the LCD substrate G. It is preferable to keep the distance between the resist discharge port 52b and the LCD substrate G constant at a distance η as a whole in the Y direction passing through the Q point by tilting the nozzle 52.

  However, in the X direction, there is a shift of the distance δ between the position where the displacement sensors 58a and 58b measure the waviness of the LCD substrate G and the position of the resist discharge port 52b of the resist nozzle 52. This is because it is difficult to detect the undulation of the LCD substrate G immediately below the resist discharge port 52b in terms of the apparatus configuration, and even if the undulation of the LCD substrate G immediately below the resist discharge port 52b can be detected, the resist When the posture correction of the nozzle 52 is performed, since the registration nozzle 52 is scanned in the X direction at a constant speed, it has already passed the measurement point when the posture correction is completed. The meaning of performing 52 posture correction is lost.

  For this reason, when the resist discharge port 52b of the resist nozzle 52 reaches the point Q, the first and second lifting control devices 55a and 55a are arranged so that the posture of the resist nozzle 52 is in the state shown in FIG. It is necessary to adjust the timing of the lift drive by 55b.

  Therefore, as previously shown in FIG. 3, the measurement signal of the displacement sensor 58a is sent to the first buffer device 86a, where a delay process for a predetermined time is performed, and then sent to the first lifting control device 55a. Similarly, the measurement signal of the displacement sensor 58b is sent to the second buffer device 86b, where a delay process for a predetermined time is performed, and then sent to the second lifting control device 55b. The signal delay time in the first and second buffer devices 86a and 86b includes the reading value of the linear scale 83 by the head 84, the scanning speed of the resist nozzle 52, and the distance δ between the resist discharge port 52b and the displacement sensors 58a and 58b. The delay time generator 87 determines the speed based on the calculation speeds of the first and second lifting / lowering control devices 55a and 55b. Once the signal delay time is optimally determined, it is not necessary to change unless the scanning conditions of the resist nozzle 52 are changed.

  The first elevating control device 55a that has received the delay-measured measurement signal output from the first buffer device 86a uses the delay-processed measurement signal and the signal from the encoder unit of the first nozzle elevating mechanism 54a to determine the first A drive signal for driving the motor unit of the one-nozzle lifting mechanism 54a is generated and output to the motor unit. Similarly, the second lift control device 55b that has received the measurement signal after delay processing output from the second buffer device 86b receives the measurement signal after delay processing and the signal from the encoder section of the second nozzle lifting mechanism 54b. Then, a drive signal for driving the motor unit of the second nozzle lifting mechanism 54b is generated and output to the motor unit.

  Thus, when the resist discharge port 52b of the resist nozzle 52 reaches the Q point, the distance between the resist discharge port 52b and the LCD substrate G is generally constant at the distance η in the Y direction passing through the Q point. The attitude of the resist nozzle 52 can be controlled. By performing such height control and posture control of the resist nozzle 52 at a constant period (that is, the sampling period of the displacement sensors 58a and 58b) while the resist nozzle 52 scans the LCD substrate G, The distance between the surface of the LCD substrate G and the resist discharge port 52b can be kept constant throughout the LCD substrate G, and a uniform coating film with no unevenness in thickness can be formed.

  As a drive signal for driving the motor units of the first and second nozzle lifting mechanisms 54a and 54b, a speed signal for controlling the positions of the holding members 62a and 62b and a moving speed of the holding members 62a and 62b are used. Acceleration signal to be controlled. For example, when the horizontal axis represents the scanning time t of the resist nozzle 52 and the vertical axis represents the displacement amount Z (swell of the LCD substrate G) measured by the displacement sensor 58a, the sampling period Ts by the displacement sensor 58a is calculated from these relationships. A speed signal for raising and lowering the first nozzle raising and lowering mechanism 54a can be obtained by a linear approximation that divides the displacement amount ΔZ at the sampling period Ts. A speed signal for raising and lowering the second nozzle raising and lowering mechanism 54b can be calculated in the same manner.

  Further, when the displacement amount ΔZ exceeds the actual undulation amount of the LCD substrate G, for example, when a displacement amount exceeding ± 50 μm is measured at a sampling period of 1 Hz (that is, a relationship of ΔZ> 50 μm / Ts). When the equation is satisfied), a command to stop the first and second nozzle lifting mechanisms 54a and 54b is sent from the first and second lifting control devices 55a and 55b to the first and second nozzle lifting mechanisms 54a and 54b, respectively. It is preferable to be sent to the motor unit.

Next, the processing flow of the LCD substrate G in the resist processing unit 10 will be briefly described below.
First, the resist nozzle 52 is kept waiting in the nozzle bath of the nozzle cleaning unit 57. For example, when the transfer arm holding the LCD substrate G enters from above the mounting table 51 in the Y direction, the elevating pins 61 are lifted to support the LCD substrate G. Then, after the transfer arm is withdrawn, the lift pins 61 are lowered to place the LCD substrate G on the mounting table 51, and the LCD substrate G is sucked and fixed onto the mounting table 51 by suction from the suction holes.

  Next, after performing a dummy dispense of the resist nozzle 52 in the nozzle cleaning unit 57, the resist nozzle 52 is moved to the reduced pressure drying device (VD) 12 side of the mounting table 51 to apply a resist solution to the LCD substrate G. The resist nozzle 52 is set at a predetermined initial height position. Subsequently, while the resist nozzle 52 is scanned toward the nozzle cleaning unit 57 at a predetermined speed, sensing by the displacement sensors 58a and 58b is performed at a predetermined sampling period, and the above-described processing is performed in response to the undulation of the LCD substrate G. A coating film is formed on the LCD substrate G by discharging the resist solution from the resist discharge port 52b while controlling the operation of the first and second nozzle lifting mechanisms 54a and 54b.

  When the formation of the coating film is completed, the resist nozzle 52 is moved to the nozzle cleaning unit 57, where nozzle cleaning is performed, and the nozzle bus is again waited. The LCD substrate G on which the coating film is formed is lifted to a predetermined height by the lift pins 61 and then held by the substrate transport device 13 and placed on the placement table 68 of the vacuum drying device (VD) 12. Is housed in. And the volatile component contained in a coating film is evaporated by hold | maintaining the inside of the chamber 69 in a pressure-reduced atmosphere. The LCD substrate G that has been subjected to such a drying process is unloaded from the reduced-pressure drying apparatus (VD) 12 to, for example, an apparatus that performs a thermal drying process of the coating film by a substrate transfer apparatus (not shown).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such a form. For example, in the above description, the position of the resist nozzle 52 is controlled by using the two displacement sensors 58a and 58b and independently controlling the first and second nozzle elevating mechanisms 54a and 54b. One displacement sensor is provided at the center, whereby the undulation of the LCD substrate G is measured at the center of the LCD substrate G, and the first and second nozzle lifting mechanisms 54a and 54b are synchronized and controlled based on the measured values. May be.

  In the above description, the calculation process for generating the drive signal of the first nozzle lifting mechanism 54a is performed in the first lift control device 55a. However, the signal is detected in the first buffer device 86a that has received the detection signal of the displacement sensor 58a. In addition to the delay process, the speed signal may be converted by performing a differentiation process. In this case, the signal output from the encoder unit of the first nozzle lifting mechanism 54a is also differentiated and converted into a speed signal before being input to the first lifting control device 55a. Thereby, the calculation load in the 1st raising / lowering control apparatus 55a can be made small. It is preferable to similarly control the second nozzle lifting mechanism 54b.

  Furthermore, although the encoder part which these have was used for the drive control of the 1st, 2nd nozzle raising / lowering mechanism 54a * 54b, the high-resolution linear scale is arrange | positioned separately, and the measured value by the linear scale is 1st *. It is also preferable to use it for drive control of each motor part of the second nozzle lifting mechanism 54a, 54b. Furthermore, it is good also as a structure which can switch and use such a linear scale and the encoder part which the 1st, 2nd nozzle raising / lowering mechanism 54a * 54b each comprises. In this case, for example, an encoder unit is used in a normal coating film forming process, and a linear scale is used in a coating film forming process that requires very high film thickness uniformity.

  Furthermore, in the above embodiment, the height of both ends of the resist nozzle 52 is finely adjusted independently according to the sampling period based on the measurement values of the displacement sensors 58a and 58b. As long as is obtained, the following two control methods can be used.

  The first control method is that the distance between the resist discharge port 52b on the first nozzle lifting mechanism 54a side of the LCD substrate G and the LCD substrate G is in the range of η ± κ, and the second nozzle lifting / lowering of the LCD substrate G is performed. When the distance between the resist discharge port 52b on the mechanism 54b side and the LCD substrate G is also within the range of η ± κ, control is performed so as not to drive the first and second nozzle elevating mechanisms 54a and 54b. It is a method to do. In this case, it is preferable to determine the value of η ± κ so that the resist nozzle 52 does not tilt beyond a certain angle.

  Another control method is to average the measured values of the displacement sensors 58a and 58b, and synchronize the first nozzle lifting mechanism 54a and the second nozzle lifting mechanism 43b so that the posture of the registration nozzle 52 is always held in a horizontal posture. In this method, the distance between the average height of the undulation of the LCD substrate G and the resist discharge port 52b is kept constant by moving up and down. In this case, when the difference between each measured value by the displacement sensors 58a and 58b and the average value thereof becomes larger than a predetermined value, an alarm is issued or the discharge of the resist solution from the resist nozzle 52 is stopped. It is preferable to take measures such as

  In the above description, the case where the LCD substrate G mounted on the mounting table 51 is wavy has been described. However, the LCD substrate G has a thickness of, for example, several tens of μm due to the glass substrate manufacturing method. Mostly, unevenness exists. For this reason, even when the LCD substrate G is mounted on the mounting table 51 without undulations, if the coating processing method according to the present invention is used, the LCD substrate G itself has excellent uniformity corresponding to the thickness unevenness of the LCD substrate G itself. A coated film can be formed.

  In the above description, the configuration in which the resist nozzle 52 is scanned on the fixed LCD substrate G is described as an example. However, the resist nozzle 52 may be fixed and the mounting table 51 may be scanned. The present invention also relates to a configuration in which a resist solution is applied to the LCD substrate G using an air stage that blows air or nitrogen gas from the surface and sliding the LCD substrate G on the air stage. A coating method can be used.

  Further, in the above description, the resist film is taken up as the coating film. However, the coating film is not limited to this, and may be an antireflection film, an insulating film having no photosensitivity, or the like.

  The present invention is suitable for a resist film forming apparatus that forms a coating film such as a resist film on a large substrate such as an LCD glass substrate.

The top view which shows schematic structure of a resist processing unit. The front view which shows schematic structure of a resist coating apparatus. The control block diagram of a resist coating device. The perspective view which shows schematic structure of a resist nozzle. The side view which shows the positional relationship of a displacement sensor and a resist nozzle. FIG. 5A is a cross-sectional view showing a state where the resist discharge port of the resist nozzle is located on the point P shown in FIG. 5, and FIG. 5B is a view showing the resist discharge port of the resist nozzle located on the point Q shown in FIG. FIG.

Explanation of symbols

10; resist processing unit 11; resist coating apparatus (CT)
12: Vacuum drying equipment (VD)
13; substrate transfer device 51; mounting table 52; resist nozzle 53; resist solution supply mechanism 54a; first nozzle lifting mechanism 54b; second nozzle lifting mechanism 55a; first lifting control device 55b; second lifting control device 56; Slide mechanism 57; Nozzle cleaning units 58a and 58b; Displacement sensor 59; Application processing control device 86a; First buffer device 86b; Second buffer device 87; Delay time generating device G;

Claims (9)

A coating film forming apparatus for forming a coating film by supplying a predetermined coating liquid to a substrate held in a substantially horizontal posture,
A coating liquid nozzle having a coating liquid discharge port for discharging a predetermined coating liquid;
A nozzle lifting mechanism for lifting and lowering the coating liquid nozzle;
A lifting control device for performing lifting control of the nozzle lifting mechanism;
A moving mechanism for relatively moving the substrate and the coating liquid nozzle;
A displacement sensor for measuring the waviness of the substrate in a predetermined distance forward from the coating liquid discharge port in the direction in which the coating liquid is applied by the coating liquid nozzle;
A buffer device for performing a delay operation for a predetermined time on the measurement value by the displacement sensor and sending the delay signal to the elevation control device;
A delay time generating device for determining a delay time in the buffer device;
Comprising
When forming the coating film on the surface of the substrate by relatively moving the substrate and the coating solution nozzle while discharging the coating solution from the coating solution nozzle, the elevating control device is configured to use the coating solution nozzle. A coating film forming apparatus, wherein the coating liquid nozzle is moved up and down in accordance with the undulation of the substrate so that the distance between the coating liquid discharge port and the substrate is constant.   The delay time generation device includes a relative moving speed between the substrate and the coating liquid nozzle by the moving mechanism, and a horizontal distance between the coating liquid discharge port of the coating liquid nozzle and the displacement sensor. The coating film forming apparatus according to claim 1, wherein a delay time in the buffer device is determined based on the determination.   The coating film forming apparatus according to claim 1, wherein the displacement sensor is attached to the coating liquid nozzle. The nozzle lifting mechanism has a drive part and an encoder part,
A linear scale for measuring the height of the coating liquid nozzle, and a switch for switching between the encoder unit of the nozzle lifting mechanism and the linear scale,
The lifting control device uses the measured value of either the encoder unit of the nozzle lifting mechanism or the linear scale selected by the switch to generate a control signal for driving the driving unit of the nozzle lifting mechanism. The coating film forming apparatus according to any one of claims 1 to 3, wherein the coating film forming apparatus is generated. A coating film forming apparatus for forming a coating film by supplying a predetermined coating liquid to a substrate held in a substantially horizontal posture,
An elongated coating liquid nozzle having a coating liquid discharge port for discharging a predetermined coating liquid in a substantially strip shape;
A first nozzle lifting mechanism that substantially holds one end of the coating liquid nozzle in the longitudinal direction and lifts the coating liquid nozzle;
A second nozzle raising / lowering mechanism that substantially holds the other end in the longitudinal direction of the coating liquid nozzle and raises and lowers the coating liquid nozzle;
A first elevating control device for performing elevating control of the first nozzle elevating mechanism;
A second lifting control device for performing lifting control of the second nozzle lifting mechanism;
A moving mechanism including a motor and a linear scale for relatively moving the substrate and the coating liquid nozzle;
A first displacement sensor and a second displacement sensor for measuring the waviness of the substrate at a predetermined distance in front of the coating solution discharge port in the direction in which the coating solution is applied by the coating solution nozzle and at the end of the substrate;
A first buffer device that performs a delay operation for a predetermined time on a measured value by the first displacement sensor, and sends the delay signal to the first lifting control device;
A second buffer device that performs a delay operation for a predetermined time on a measurement value obtained by the second displacement sensor, and sends the delay signal to the second lift control device;
A delay time generating device for determining a delay time in the first buffer device and the second buffer device;
Comprising
When forming a coating film on the surface of the substrate by relatively moving the substrate and the coating solution nozzle while discharging the coating solution from the coating solution nozzle, the first elevating control device and the second The elevation controller controls the elevation and inclination of the coating solution nozzle in accordance with the undulation of the substrate so that the distance between the coating solution discharge port of the coating solution nozzle and the substrate is constant. A coating film forming apparatus.   The delay time generation device includes a relative moving speed between the substrate and the coating liquid nozzle by the moving mechanism, and a horizontal position between the first and second displacement sensors and the coating liquid discharge port of the coating liquid nozzle. 6. The coating film forming apparatus according to claim 5, wherein a delay time in the first and second buffer devices is determined based on a directional distance.   7. The coating film forming apparatus according to claim 5, wherein the first and second displacement sensors are respectively attached in the vicinity of end portions in the longitudinal direction of the coating liquid nozzle. Each of the first and second nozzle lifting mechanisms has a drive unit and an encoder unit,
A first linear scale that measures the height of one end of the coating liquid nozzle; a second linear scale that measures the height of the other end of the coating liquid nozzle; an encoder unit of the first nozzle lifting mechanism; and the first A first switch for switching between the linear scale, and a second switch for switching between the encoder unit of the second nozzle lifting mechanism and the second linear scale,
The first and second lifting control devices measure either the encoder unit of the first or second nozzle lifting mechanism selected by the first or second switch or the first or second linear scale. 8. The coating film formation according to claim 5, wherein a control signal for driving the drive unit of the first and second nozzle lifting mechanisms is generated using the value. 9. apparatus.   When the difference between the height of one end of the coating liquid nozzle and the height of the other end is equal to or greater than a predetermined value, the first and second lift control devices 9. The coating film forming apparatus according to claim 5, wherein the operation is stopped.

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